The present invention relates to a bobbin tube receiver for a textile spinning or winding machine and, more particularly, to an improvement in a bobbin tube receiver of the type disclosed in German Gebraushmuster 73 00 246.
In textile winding operations wherein a yarn is to be rewound onto a bobbin tube, it is necessary not only to catch the leading yarn end but also in many instances to fix the yarn end on the tube foot in the form of a yarn reserve that can be readily removed by hand. German DE-A 25 06 291 suggests to this end, for example, that the yarn end caught by a catch nose member be overwound by a yarn reserve. Then, during further processing of the completely wound bobbin tube, the yarn end can be grasped by hand and joined to the leading yarn end of a following bobbin.
The automatic receipt of the yarn end by the bobbin tube is explained in an embodiment in German DE-A 25 06 291 for the production of starter bobbins for open end spinning machines. However, the catching of the yarn end and the placing of a yarn reserve which overwinds the yarn end are also known in cheese changers in automatic bobbin winding machines like those known from German DE 37 33 353 A1. In both devices, the tube to be rewound is wound with the yarn reserve outside of the bobbin receiver of the winding head and, after this operation has taken place, the tube is transferred to the actual tube receiver of the machine.
High demands are placed on the yarn reserve and the ability to grasp the yarn end. On one hand, the yarn reserve should be wound sufficiently firmly on the tube foot that it does not come loose during transportation and handling of the finished bobbins. On the other hand, the yarn end must be able to be readily grasped and removed from the tube foot. Moreover, the yarn end should not be damaged in order that it does not cause any errors during further processing.
It can occur in the known devices that the leading yarn end is incorrectly clamped on the side of the tube because of yarn tension fluctuations, which causes the yarn end to come loose during winding and wrap around the tube so that the yarn end is wound into the bobbin. It can also occur that the clamped yarn end is rubbed apart during winding by means of a slight relative motion between the tube and the tube carrier. The yarn reserve can then come loose and be lost or difficult to find. When a catch nose is used, the length of the free yarn end is not optimally controlled and, if it is too long, can whip into the yarn windings.